Bacterial leaf spot bacterium (Xanthomonas axonopodis pv. vignaeradiatae) of green gram caused considerable damage every year during Kharif season and sometimes become very severe, which results in heavy loss in grain yield. The maximum mean per cent disease index was observed in Vallabhnagar followed by Kotra, Mavli, Jhadol, Gogunda, Salumber Tehsil and least percent disease index was observed at Kherwara Tehsil of Udaipur districts during surveys in the years i.e. 2013 and 2014.The per cent disease index varied from 07.56 - 32.60 and 08.56 - 29.42 in the years 2013 and 2014, respectively. The overall disease severity was more in 2013 as compared to 2014.
Int.J.Curr.Microbiol.App.Sci (2018) 7(3): 2924-2931 International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume Number 03 (2018) Journal homepage: http://www.ijcmas.com Original Research Article https://doi.org/10.20546/ijcmas.2018.703.338 Severity of Bacterial Leaf spot (Xanthomonas axonopodis pv vignaeradiatae) of Green gram in Different Tehsils of Udaipur District, Rajasthan Jitendra Kumar* and Anila Doshi Department of Plant Pathology, Rajasthan College of Agriculture, MPUAT, Udaipur-313001, India *Corresponding author email id: jitpatho@gmail.com ABSTRACT Keywords Green gram, Bacterial leaf spot, Per cent disease index, Survey Article Info Accepted: 24 February 2018 Available Online: 10 March 2018 Bacterial leaf spot bacterium (Xanthomonas axonopodis pv vignaeradiatae) of green gram caused considerable damage every year during Kharif season and sometimes become very severe, which results in heavy loss in grain yield The maximum mean per cent disease index was observed in Vallabhnagar followed by Kotra, Mavli, Jhadol, Gogunda, Salumber Tehsil and least percent disease index was observed at Kherwara Tehsil of Udaipur districts during surveys in the years i.e 2013 and 2014.The per cent disease index varied from 07.56 - 32.60 and 08.56 29.42 in the years 2013 and 2014, respectively The overall disease severity was more in 2013 as compared to 2014 Introduction Green gram [Vigna radiata (L.) Wilczek] is one of the important pulse crop in India, which has been cultivated since ancient times It is widely cultivated throughout the Asia, including India, Pakistan, Bangladesh, Sri Lanka, Thailand, Cambodia, Indonesia, Malaysia and south China In India, it is grown over on an area of 34.4 lac hectares with a production of 14 lac tones and with average productivity 406.98 kg/ha The major growing states of green gram are Rajasthan (30.81%), Maharashtra (19.51%), Karnataka (15.35%), Andhra Pradesh (12.79%), Orissa (7.41%), Tamil Nadu (4.97%) and Uttar Pradesh (2.09%), respectively (Anon., 2014a) In Rajasthan, it is cultivated on 8.93 lac hectares with production of 4.23 lac tones The major growing districts are Nagaur, Jodhpur, Pali, Jaipur, Udaipur, Chittorgarh, Banswara and Barmer (Anon., 2014b) Green gram is well suited to a large number of cropping system and a popular cereal-based diets due to easily digestible, rich in protein (25-28%), oil (1.0- 1.5%), fiber (3.5-4.5%), ash (4.5-5.5%) and carbohydrates (62-65%) on dry weight basis (Singh et al., 2010) Green gram is more palatable, nutritive, digestible and non-flatulent than other pulses (Anjum et al., 2006) It not only plays an important role 2924 Int.J.Curr.Microbiol.App.Sci (2018) 7(3): 2924-2931 in human diet but also in improving the soil fertility by fixing the atmospheric nitrogen (Muhammad et al., 2004) Inadequate nutrient status of soil is a particular problem for small landholders of the developing countries, where much grain-legume production occurs (Peter and Vance, 2003) Green gram plant suffers from two bacterial disease namely, bacterial leaf spot and halo blight (Pseudomonas syringae pv phaseolicola) Out of these two diseases the former is economically more important and widespread in India (Thind, 2012) Bacterial leaf spot pathogen produces symptoms on leaves, stems, pods and seeds Small watersoaked spots are the initial symptoms observed on leaves and appear within to 10 days of infection These spots enlarge and the centre turns necrotic and brown, areas around the lesion may become flaccid The lesion is surrounded by a narrow band of bright yellow tissue; stem infection is less common and begins as a water-soaked spot, which becomes reddish-brown and usually without chlorosis Stem girdling may develop at the cotyledonary node (Patel and Jindal, 1972; Chand, 1986) Bacterial leaf spot caused by Xanthomonas axonopodis pv vignaradiatae (Vauterin et al., 1995) is an important seed borne disease and frequently causes considerable reduction in yield and economic loss to the growers The pathogen is disseminated to new areas through infected seeds (Shekhawat and Patel, 1977), whereas local spread occurs through spattering rains (Chand, 1986) It has assumed considerable importance as it becomes destructive and devastative particularly under favourable environmental conditions Soni and Thind (1991) detected bacterial pathogen of green gram from seeds by using bacteriophages The bacterium was detected in shrivelled and discoloured seeds The pathogen was identified as Xanthomonas campestris pv vignaradiatae Patro (2004) reported leaf spot as serious problem of green gram cultivation both in India and elsewhere Seed and soil borne organisms singly or in combination caused the seedling disease complex of this crop resulting in partial or complete loss of crop stand Annual yield loss due to bacterial leaf spot ranged from 5-25%, but under severe infection on highly susceptible variety yield loss gone up to 100% Thind (2012) described symptoms of bacterial leaf spot of green gram The symptoms of leaf spot were in the form of brown, circular to irregular and raised spots Generally the spots were dry and necrotic from the beginning of their formation but sometimes they were water soaked or had translucent border They appeared on either surface as superficial eruption but gradually developed through the entire thickness of the leaflet and become corky and rough The disease did not cause defoliation and dark cankers were developed and often extending from soil level to the growing tips Lesions on the pods were brown raised but were seen rarely in nature Disease had been found on all parts of green gram plants As the pathogen is largely parenchymatous, infected plants are not completely killed However, severe infections results in the necrosis of considerable leaf area leading to the reduction in photosynthesis and general weakening of the plants Materials and Methods Survey’s were conducted to know the distribution and prevalence of bacterial leaf spot of green gram during the kharif season of 2013-14 and 2014-15 in green gram growing areas of Udaipur district, which includes Tehsil viz., Mavli, Vallabhnagar, Gogunda, Jhadol, Kherwara, Kotra and Salumber The disease severity in the plants was recorded at 30 days after sowing till maturity stage by 2925 Int.J.Curr.Microbiol.App.Sci (2018) 7(3): 2924-2931 randomly selecting five spots in every field and closely examining 20 plants in each of the four directions of the selected point Severity of disease in a field was recorded as percentage of lesion area infected out of total leaf area examined The Typical symptoms of bacterial leaf spot of green gram on cotyledons, stem, pods and leaves are described in Figure The disease situation for each plant was noted on an arbitrary scale of 0-5 The disease rating key was used based on leaf spot disease development in which infected plants were categorized in arbitrary classes Natural symptoms of disease were recorded during this period The disease severity was recorded by using the following scale (Rathore, 2006) The entire data were pooled together and per cent disease index was calculated by using following formula (Wheeler, 1969) Sum of individual disease ratings Per cent disease index = x 100 Total no of plants leaves assessed x Maximum disease rating Results and Discussion An intensive survey to record the disease severity were carried out for consecutive two years during Kharif 2013 and 2014 in major green gram growing areas of Mavli, Vallabhnagar, Gogunda, Jhadol, Kherwara, Kotra and Salumber Tehsil of Udaipur district to estimate the disease prevalence The per cent disease index for green gram bacterial leaf spot disease was noticed in all the locations surveyed ranging from 5.50 to 38.36 and 7.30 to 34.60 PDI in the year 2013 and 2014, respectively which indicates its distribution and occurrence in large areas It was observed that average disease severity was more between 30 to 60 days old crop The severity data also indicate that the disease initiation was at 20-30 days after sowing (Fig 1) In the year 2013, the maximum mean per cent disease index (38.36) was observed in Sarjana village of Vallabhnagar Tehsil followed by Bhatewar (36.90 PDI), Jura (28.46 PDI), Dabok (26.40 PDI), Bikarni (24.03 PDI), Akodara (22.55 PDI), Amli (19.29 PDI), Jaswantgarh (18.56 PDI), Phalasiya (18.05 PDI), Mavli (17.80 PDI), Amaliya (16.87 PDI), Cheetarawas (16.78 PDI), Mandwa (16.60 PDI), Jhadol (14.55 PDI), Devgaon (12.50 PDI), Saradi (11.46 PDI, Sundara (10.50 PDI), Semar (09.23 PDI), Thana (06.68), Jaitpura (06.70 PDI) and least percent disease index was observed at Badla village (05.50 PDI) (Table 1) In the year 2014, the maximum mean per cent disease index (34.60) was observed in Bhatewar village of Vallabhnagar Tehsil followed by Sarjana (29.36), Mavli (26.80 PDI), Jura (26.46 PDI), Akodara (24.30 PDI), Mandwa (22.70 PDI), Jaswantgarh (19.50 PDI), Amli (19.20 PDI), Cheetarawas (17.80 PDI), Bikarni (17.40 PDI), Jaitpura (16.40 PDI), Amaliya (15.80 PDI), Phalasiya (14.60 PDI), Dabok (14.40 PDI), Semar (12.28 PDI), Jhadol (12.00 PDI), Devgaon (10.60 PDI), Sundara (09.50 PDI), Saradi (07.30 PDI), Badla (05.50 PDI) and least percent disease index was observed at Thana (07.40 PDI) (Table 2) On the basis of Tehsil wise mean data, in the year 2013, maximum per cent disease index (32.60 PDI) was recorded in Vallabhnagar Tehsil followed by Kotra (23.03 PDI), Mavli (21.16 PDI), Jhadol (16.49 PDI), Gogunda (14.85 PDI), Salumber (10.22 PDI) and least PDI was observed at Kherwara Tehsil (07.56 PDI) 2926 Int.J.Curr.Microbiol.App.Sci (2018) 7(3): 2924-2931 Disease rating scale of leaf spot of green gram No infection Minute water soaked spots scattered over the leaves covering about 1-10% leaf area Little bigger spots covering about 10-25% leaf area Bigger leaf spot covering about 25-50% leaf area, few small spots on petiole and stem initiated About 50-75% leaf area covered by heavy necrotic spotting, distinct enlarged elliptical lesion on petiole and stem Above 75% leaf area covered with necrotic leaf spots, cracking of stem, leaf spot or infection on pods Table.1 Distribution and prevalence of bacterial leaf spot of green gram at different locations of Udaipur district during Kharif season of 2013 Tehsil Name of the village Mavli Mavli Dabok Amli Mean Akodara Sarjana Bhatewar Mean Jaswantgarh Semar Cheetarawas Mean Phalasiya Jhadol Amaliya Mean Badla Thana Sundara Mean Mandwa Bikarni Jura Mean Jaitpura Saradi Devgaon Mean Vallabhnagar Gogunda Jhadol Kherwara Kotra Salumber Cultivars/ Variety Crop stage Area (ha) RMG-62 SML-668 RMG-62 Grand growth stage Flowering stage Grand growth stage 2.00 1.50 2.00 SML-668 GM-4 SML-668 Grand growth stage Flowering stage Flowering stage 1.50 0.50 2.00 SML-668 Local GM-4 Maturity stage Pod formation stage Maturity stage 1.50 0.50 2.00 RMG-268 RMG-62 Local Pod formation stage Grand growth stage Pod formation stage 1.50 3.00 1.50 Local K-851 Local Flowering stage Flowering stage Pod formation stage 0.50 1.00 2.00 Local SML-668 RMG-62 Pod formation Stage Maturity stage Maturity stage 1.25 0.25 2.00 Local SML-668 Local Pod formation stage Maturity stage Maturity stage 1.50 0.50 0.75 SEm± CD at 5% CV% * Figures in the parenthesis are arc sin transformed values 2927 Mean per cent disease index (PDI) 17.80 (24.94)* 26.40 (30.90) 19.29 (26.04) 21.16 22.55 (28.34) 38.36 (38.26) 36.90 (37.39) 32.60 18.56 (25.50) 09.23 (17.67) 16.78 (24.17) 14.85 18.05 (25.13) 14.55 (22.41) 16.87 (24.24) 16.49 05.50 (13.55) 06.68 (14.97) 10.50 (18.90) 07.56 16.60 (24.03) 24.03 (29.34) 28.46 (32.17) 23.03 06.70 (14.99) 11.46 (19.78) 12.50 (20.41) 10.22 0.4155 1.1594 5.38 Int.J.Curr.Microbiol.App.Sci (2018) 7(3): 2924-2931 Table.2 Distribution and prevalence of bacterial leaf spot of green gram at different locations of Udaipur district during Kharif season of 2014 Tehsil Name of the village Cultivars/ Variety Mavli Mavli Dabok Amli RMG-62 Local Local Mean Vallabhnagar Akodara Sarjana Gogunda Jhadol Kherwara Bhatewar Mean Jaswantgarh Semar Cheetarawas Mean Phalasiya Jhadol Amaliya Mean Badla Thana Kotra Sundara Mean Mandwa Bikarni Jura Salumber Mean Jaitpura Saradi Devgaon Mean Crop stage Maturity stage Flowering stage Pod formation stage Area (ha) Mean per cent disease index (PDI) 1.00 0.50 2.00 26.80 (31.17)* 14.40 (22.29) 18.20 (25.24) 19.80 24.30 (29.52) 29.36 (32.75) Local GM-4 Grand growth stage Flowering stage 1.50 2.50 Local Flowering stage 2.00 SML-668 Local GM-4 Maturity stage Pod formation stage Maturity stage 1.50 2.50 2.00 34.60 (35.95) 29.42 19.50 (26.19) 12.28 (20.50) 17.80 (24.94) 16.52 14.60 (22.45) 12.00 (20.25) 15.80 (23.41) 14.13 08.80 (17.25) 07.40 (15.77) RMG-268 RMG-62 Local Pod formation stage Grand growth stage Pod formation stage 1.50 2.25 1.50 Local Local Flowering stage Flowering stage 2.00 0.50 SML-668 Pod formation stage 2.00 Local Local RMG-62 Pod formation Stage Flowering stage Maturity stage 1.25 0.50 1.00 09.50 (17.94) 08.56 22.70 (28.44) 17.40 (24.64) 26.46 (30.82) 22.18 16.40 (23.76) 07.30 (15.67) Local SML-668 Pod formation stage Flowering stage 2.50 0.75 Local Flowering stage 2.00 SEm± CD at 5% CV% * Figures in the parenthesis are arc sin transformed values 2928 10.60 (18.99) 11.43 0.5099 1.4229 6.67 Int.J.Curr.Microbiol.App.Sci (2018) 7(3): 2924-2931 Fig.1 Distribution and prevalence of bacterial leaf spot of green gram at different locations of Udaipur district during Kharif season, 2013 and 2014 Fig.2 Typical symptoms of bacterial leaf spot of green gram on cotyledons, stem, pods and leaves 2929 Int.J.Curr.Microbiol.App.Sci (2018) 7(3): 2924-2931 During survey in Kharif 2014, similar pattern of disease occurrence was recorded from all these location with maximum per cent disease index (29.42 PDI) in Vallabhnagar Tehsil followed by Kotra (22.18 PDI), Mavli (19.80 PDI), Gogunda (16.52 PDI), Jhadol (14.13 PDI), Salumber (11.43 PDI) and least PDI was observed at Kherwara Tehsil (08.56 PDI) From this survey it was observed that this disease was severe and appears in damaging form during Kharif, 2013 Whereas, disease severity was reduced during Kharif 2014 From these studies it can be predicted that environmental factors are critical for occurrence and spread of disease in epidemic form (Table and 2) Survey for occurrence and distribution of disease was necessary because there are very limited published reports and records are available on this disease in Rajasthan However, it was cultivated in wide area in Rajasthan but it is a kind of glimpse of the loss it causes due to this disease The disease incidence varied from locality to locality, because of cropping pattern, environmental conditions, use of different varieties and buildup of inoculum load It was observed during the survey that incidence of disease was negligible up to July This clearly indicated that the disease intensity depends on factors like location, cultural practices followed by use of infected seeds of susceptible variety, improper drainage and meteorological factors like temperature, relative humidity and rainfall In general, it was observed that disease incidence was maximum during July-August which coincides with heavy rains and cloudy weather During survey it has been observed that Bacterial leaf spot incidence was more in Kharif season i.e., wherever rainfall was more during the season The disease incidence was more because of suitable environmental parameters for development of the pathogen Incidence of the disease was less wherever improved varieties were used and early sowing has been practiced indicating the importance of proper selection of cropping season and disease free seeds helping in managing bacterial leaf spot disease of green gram From survey’s, in Kharif season of 2013 and 2014 it has been found that bacterial leaf spot incidence was present in almost all Tehsil wherever the green gram was cultivated The disease severity was highest in Vallabhnagar and Mavli whereas, it was less in Kherwara Tehsil of Udaipur district, Rajasthan In the years 2013, there was more rainfall as compared to 2014 in all the locations surveyed in Udaipur district Interestingly, there were 2-3 spells of heavy rains which caused heavy disease severity in 2013 The per cent disease index ranges varied from 5.50 to 38.36 and 7.30 to 34.60 in the both years i.e 2013 and 2014, respectively Hence, disease severity ranges indicate that favorable climate and infected seeds are important factors of disease Similar observations were made by Patro (2004), who reported the bacterial leaf spot of green gram caused by X axonopodis pv vignaeradiatae and opined that the pathogen was carried within the seed and spreads in the field by moisture propelled wind Annual yield loss due to bacterial leaf spot ranged from 525%, but under severe infection on highly susceptible variety yield loss gone up to 100% Rathore (2010) reported the occurrence of leaf spot on green gram caused by X axonopodis pv vignaeradiatae in Jodhpur, Rajasthan for the first time during Kharif season 2006 as circular, necrotic, corky leaf spots, surrounded by a thin water soaked hallow on green gram plants with an incidence of 6.1 to 24.9 PDI at various stages of infection in different green gram cultivars substantiating the results of the present survey wherein incidence varied from genotype to genotype Acknowledgement The authors are highly grateful to the higher authorities of the University and other faculty members for facilitating required needs as well as rendering moral support during the entire research work 2930 Int.J.Curr.Microbiol.App.Sci (2018) 7(3): 2924-2931 References Anjum, M S., Ahmed, Z I and Rauf, C A 2006 Effect of Rhizobium inoculation and nitrogen fertilizer on yield and yield components of mungbean International Journal of Agriculture & Biology 8: 238240 Anonymous, 2014a Annual report for the year 2013-2014 Department of agriculture and cooperation, Ministry of agriculture, Government of India, Krishi Bhawan, New Delhi, Pp 20-47 Anonymous, 2014b Rajasthan Agriculture statistics at a glance for the 2013-2014 Directorate of agriculture, Rajasthan, Jaipur Pp, 74-75, 83 Chand, J N 1986 Bacterial disease of legume and their management Indian Journal of Mycology and Plant Pathology 30: 1921 Muhammad, A N., Rashid, A and Ahmad, M S 2004 Effect of seed inoculation and different fertilizer levels on the growth and yield of mungbean (Vigna radiata L.) Journal of Agronomy 3: 40-42 Patel, P N and Jindal, J K 1972 Bacterial leaf spot and halo blight disease of mungbean and other legume in India Indian Phytopathology.25: 526-529 Patro, T S S K 2004 Plasmid-borne determinant of antibiosis in phylloplane Bacillus sp associated with mungbean against bacterial leaf spot Journal of Plant Protection 32: 96-99 Peter, H G and Vance, C P 2003 Legumes: importance and constraints to greater use Plant Physiology 131: 872-877 Rathore, B S 2006 Efficacy of streptocycline and plant extracts against bacterial leaf spot disease caused by Xanthomonas axonopodis pv Vignae radiatae of green gram Indian Phytopathology.63: 384386 Rathore, B S 2010 Efficacy of streptocycline and plant extracts against bacterial leaf spot greengram Journal of mycology and plant pathology 36: 153-156 Shekhawat, G S and Patel, P N 1977 Seed transmission and spread of bacterial blight of cowpea and mungbean and leaf spot of green gram summer and monsoon season Plant Disease Reporter 61: 390392 Singh, B B., Dixit, G P and Katiyar, P K 2010 Vigna research in India All India Coordinated Research Project on MULLaRP, IIPR, Kanpur.Pp.1 Soni, P S and Thind, B S 1991 Detection of Xanthomonas campestris pv vignae radiatae (Sabet et al.,) Dye from green gram seeds and X campestris pv vignicola (Burkh.) Dye from cowpea seeds with the help of bacteriophages Plant Dis Res 6: 6-11 Thind, B S 2012 Phytopathogenic prokaryotes and plant diseases Scientific Publishers, Jodhpur Pp.134, 401-470 Wheeler, B E J 1969 An introduction to plant diseases John Willey and Sons Ltd., London Pp 301 How to cite this article: Jitendra Kumar and Anila Doshi 2018 Severity of Bacterial Leaf Spot (Xanthomonas axonopodis pv vignaradiatae) of Green Gram in Different Tehsils of Udaipur District, Rajasthan, India Int.J.Curr.Microbiol.App.Sci 7(03): 2924-2931 doi: https://doi.org/10.20546/ijcmas.2018.703.338 2931 ... prevalence of bacterial leaf spot of green gram at different locations of Udaipur district during Kharif season, 2013 and 2014 Fig.2 Typical symptoms of bacterial leaf spot of green gram on cotyledons,... distribution and prevalence of bacterial leaf spot of green gram during the kharif season of 2013-14 and 2014-15 in green gram growing areas of Udaipur district, which includes Tehsil viz., Mavli,... seeds helping in managing bacterial leaf spot disease of green gram From survey’s, in Kharif season of 2013 and 2014 it has been found that bacterial leaf spot incidence was present in almost